Inconsistent results of RIGHT function for different datasources

The RIGHT function returns different results for different datasources. Some of those results are inconsistent with definition of the RIGHT(x,y) function.
=======
Query: SELECT intkey, RIGHT(intkey, 1) FROM table ORDER BY intkey
Teradata, SQLServer, Sybase, Ingres, MySQL, Oracle (this result is OK):
0 0
1 1
2 2
...
10 0
11 1
...
100 0
101 1
Postgres:
0 0
1 1
2 2
...
10 10
11 11
...
100 100
101 101
DB2:
0 " "
1 " "
2 " "
...
10 " "
11 " "
...
100 " "
101 " "
=====

Query:SELECT intkey, RIGHT(intkey, 2) FROM table ORDER BY intkey
SQLServer, Sybase, Ingress, MySQL, Teradata (this result is OK):
0 0
1 1
...
10 10
11 11
...
100 00
101 01
Oracle:
0 <null>
1 <null>
2 <null>
...
10 10
11 11
...
100 00
101 01
Postgres:
0 0
1 1
2 2
...
10 10
11 11
...
100 100
101 101
DB2:
0 " "
1 " "
2 " "
...
10 " "
11 " "
...
100 " "
101 " "